First, try the owners or maintenance manual with the vehicle. Next, try the on-line manual sources, such as; www.manualspace.com for the maintenance schedule.
Mercedes uses a Flexible Service System that takes into consideration your cars operating characteristics for service recommendations. They have gotten away from the 30, 60, 90,000 mile intervals. For the most part you'll just do lubrication services every 13,000 miles. For example, if you're coming up on a 39,000 mile service where they also recommend new fluid and filter in the transmission and new transfer case fluid. I recommend doing an oil and filter change in between each lubrication service. At 2 year/26,000 mile intervals they recommend a new cabin air filter. Engine air filter is recommended every 52,000 miles, fuel filter at 65,000 miles and spark plugs at 78,000 miles. Brake fluid should be changed every 2 years.